Toothbrushes are tools for dental cleaning in people's daily life. However, if toothbrushes themselves are not sufficiently clean, they will pose threat to the dental health of users. A toothbrush generally comprises a head and a handle. The head has bristles that are tightly lined. After users wash toothbrushes when they brush their teeth, toothbrushes often gather drops of water. Some users may throw drops of water out. Bristles may fail to dry timely so that they are often in a damp environment. As a result, it is highly easy for bristles to harbor bacteria, which is not favorable for dental health.